An overview of the paleo_ENSO
古ENSO的研究进展

Studies on paleo-ENSO in fields of paleoclimate, paleoceanography, geology and paleobiology in recent decades were reviewed in this paper. Those works related to paleo-ENSO are reviewed in both observation and modeling studies, expecially in some specific warm or cool geological epochs, such as early-middle Holocene, Last Glacial, Last Interglacial and Eocene. Although a variety of uncertainties were still presented in paleo-ENSO research work, the mechanism for particularly weak El Nifio variability during early-middle Holocene is investigated. Moreover, the paradoxes in other periods were categorized and addressed. Paleo- ENSO studies will improve the understanding of the interaction between ENSO cycle and climatological background, and will further complete ENSO dynamics so as to predict how El Nino, the strongest signal that affects global climate on interannual time scale, will behave on the global warming background.